Re: Debuging embedded touchpad driver

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Sun, Jul 31, 2016 at 09:48:32PM +0200, Willy Lambert wrote:
> Hi guys,
> 
> I am trying to debug an eGalax touchpad in my embedded system. What's
> strange is that the "evtest" method doesn't react when I'm touching
> (see below). I'm not sure the touchpas is alive, so I can't tell if
> it's HW or SW.
> 
> Could anyone with experience on this kind of debug help me with a test
> procedure ? I don't know what to look to identify my problem.
> 
> root@(ubiquity)():~# evtest /dev/input/event4
> Input driver version is 1.0.1
> Input device ID: bus 0x3 vendor 0xeef product 0x1 version 0x210
> Input device name: "eGalax Inc. USB TouchController"
> Supported events:
>   Event type 0 (Sync)
>   Event type 1 (Key)
>     Event code 330 (Touch)
>   Event type 3 (Absolute)
>     Event code 0 (X)
>       Value      0
>       Min        0
>       Max     4095
>     Event code 1 (Y)
>       Value      0
>       Min        0
>       Max     4095
>     Event code 47 (?)
>       Value      0
>       Min        0
>       Max        7
>     Event code 53 (?)
>       Value      0
>       Min        0
>       Max     4095
>     Event code 54 (?)
>       Value      0
>       Min        0
>       Max     4095
>     Event code 57 (?)
>       Value      0
>       Min        0
>       Max    65535
> Testing ... (interrupt to exit)
> 
> 
> More details on my setup below :
> 
> 
> 
> The kernel should have recognized the device :
> [    1.635292] hub 3-0:1.0: port 2, status 0101, change 0001, 12 Mb/s
> [    1.641396] usbtouchscreen 2-2:1.0: usb_probe_interface
> [    1.641408] usbtouchscreen 2-2:1.0: usb_probe_interface - got id
> [    1.641799] usbcore: registered new interface driver usbtouchscreen
> [    1.645880] usbhid 2-2:1.0: usb_probe_interface
> [    1.645891] usbhid 2-2:1.0: usb_probe_interface - got id
> [    1.650539] usbcore: registered new interface driver usbhid
> [    1.650545] usbhid: USB HID core driver
> [    1.659604] input: eGalax Inc. USB TouchController Pen as
> /devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/input/input3
> [    1.660740] input: eGalax Inc. USB TouchController as
> /devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/input/input4
> [    1.661541] usbhid 2-2:1.0: looking for a minor, starting at 96
> [    1.662614] hid-multitouch 0003:0EEF:0001.0001:
> input,hiddev0,hidraw0: USB HID v2.10 Pointer [eGalax Inc. USB
> TouchController] on usb-0000:00:1d.0-2/input0
> 
> 
> The "usbtouchpad" driver is loaded :

As shown by the dmesg fragment above the touchscreen is not driven by
usbtouchscreen but rather hid-multitouch driver. Benjamin might have an
idea...

> 
> root@(ubiquity)():~# lsmod
> Module                  Size  Used by
> sja1000_isa             2821  0
> sja1000                 5206  1 sja1000_isa
> can_dev                 6395  1 sja1000
> ard_usb                 6911  0
> hid_multitouch          8637  0
> usbhid                 32470  0
> usbtouchscreen         11076  0
> i915                  511371  1
> drm_kms_helper         23402  1 i915
> drm                   185361  2 i915,drm_kms_helper
> cfbcopyarea             2714  1 i915
> i2c_algo_bit            4336  1 i915
> video                   9818  1 i915
> cfbimgblt               1947  1 i915
> cfbfillrect             3142  1 i915
> 
> 
> The device is listed (it's still a mystery why the touchpad appears 2
> times as a pen and as a device) :
> 
> 
> 
> ---------------------------------------------------------------------------------------
> root@(ubiquity)():~# cat /proc/bus/input/devices
> I: Bus=0019 Vendor=0000 Product=0001 Version=0000
> N: Name="Power Button"
> P: Phys=PNP0C0C/button/input0
> S: Sysfs=/devices/LNXSYSTM:00/device:00/PNP0C0C:00/input/input0
> U: Uniq=
> H: Handlers=kbd event0
> B: PROP=0
> B: EV=3
> B: KEY=100000 0 0 0
> 
> I: Bus=0019 Vendor=0000 Product=0001 Version=0000
> N: Name="Power Button"
> P: Phys=LNXPWRBN/button/input0
> S: Sysfs=/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1
> U: Uniq=
> H: Handlers=kbd event1
> B: PROP=0
> B: EV=3
> B: KEY=100000 0 0 0
> 
> I: Bus=0010 Vendor=001f Product=0001 Version=0100
> N: Name="PC Speaker"
> P: Phys=isa0061/input0
> S: Sysfs=/devices/platform/pcspkr/input/input2
> U: Uniq=
> H: Handlers=kbd event2
> B: PROP=0
> B: EV=40001
> B: SND=6
> 
> I: Bus=0003 Vendor=0eef Product=0001 Version=0210
> N: Name="eGalax Inc. USB TouchController Pen"
> P: Phys=usb-0000:00:1d.0-2/input0
> S: Sysfs=/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/input/input3
> U: Uniq=
> H: Handlers=mouse0 event3
> B: PROP=0
> B: EV=1b
> B: KEY=c01 0 0 0 0 0 0 0 0 0 0
> B: ABS=3
> B: MSC=10
> 
> I: Bus=0003 Vendor=0eef Product=0001 Version=0210
> N: Name="eGalax Inc. USB TouchController"
> P: Phys=usb-0000:00:1d.0-2/input0
> S: Sysfs=/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/input/input4
> U: Uniq=
> H: Handlers=mouse1 event4
> B: PROP=2
> B: EV=b
> B: KEY=400 0 0 0 0 0 0 0 0 0 0
> B: ABS=2608000 3

Thanks.

-- 
Dmitry